1. Field of the Invention
The present invention generally relates to a support device for a marine propulsion system and, more particularly, to a hydraulic steering system that is attached to a swivel bracket of an outboard motor support device.
2. Description of the Related Art
Many different systems are known to those skilled in the art which provide a hydraulic steering actuator for use with outboard motors.
U.S. Pat. No. 4,041,889, which issued to Blanchard on Aug. 16, 1977, describes a marine propulsion device steering assembly. An outboard motor includes a lower unit comprising a propeller adapted for rotation under water and a swivel bracket adapted for mounting to a transom bracket for vertical tilting movement about a generally horizontal axis. A kingpin assembly including a pivot shaft is supported by the swivel bracket for rotation about a generally vertical axis, the pivot axis having fixed thereto a pinion and means for supporting the lower unit. A rack is located below the generally horizontal axis and engages the pinion.
U.S. Pat. No. 5,127,856, which issued to Kabuto et al. on Jul. 7, 1992, describes a power steering system for an outboard motor. A power steering system for an outboard motor capable of permitting an electric motor to be driven only when the driving of the electric motor is required and automatically controlling the steering force of a steering wheel depending upon the steering reaction force is described. The system is so constructed that a steering cable is moved depending upon the rotation of the steering wheel and the movement of the steering cable is detected by means of a steering force sensor, which supplies a signal to a controller. The controller controls the output of the electric motor depending upon the signal.
U.S. Pat. No. 5,244,426, which issued to Miyashita et al. on Sep. 14, 1993, describes a power steering system for an outboard motor. A power steering system for an outboard motor for steering an outboard motor disposed outside of a rear portion of a hull and usually including a manual steering system mounted upon the hull for operating a steering element so as to manually steer the outboard motor body is disclosed. A power unit is operatively connected to the manual steering system and includes an electric motor for applying a steering assist force to the manual steering system. The power unit is located at the portion of the hull capable of effectively utilizing the inner space of the hull and the electric motor of the power unit is controlled by means of a control unit in accordance with the navigation conditions of the hull and the operating conditions of the outboard motor as detected by means of suitable sensors. The sensors comprise various sensors such as, for example, a steering torque sensor and an engine speed sensor.
U.S. Pat. No. 6,183,321, which issued to Alby et al. on Feb. 6, 2001, discloses an outboard motor with a hydraulic pump and an electric motor located within a steering mechanism. It comprises a pedestal that is attached to a transom of a boat, a motor support platform that is attached to the outboard motor, and a steering mechanism that is attached to both the pedestal and the motor support platform. It comprises a hydraulic tilting mechanism that is attached to the motor support platform and to the outboard motor. The outboard motor is rotatable about a tilt axis relative to both the pedestal and the motor support platform. A hydraulic pump is connected in fluid communication with the hydraulic tilting mechanism to provide pressurized fluid to cause the outboard motor to rotate about its tilting axis. An electric motor is connected in torque transmitting relation with the hydraulic pump. Both the electric motor and the hydraulic pump are disposed within the steering mechanism.
U.S. Pat. No. 6,276,977, which issued to Treinen et al. on Aug. 21, 2001, discloses an integrated hydraulic steering actuator. The actuator is provided for an outboard motor system in which the cylinder and piston of the actuator are disposed within a cylindrical cavity inside a cylindrical portion of the swivel bracket. The piston within the cylinder of the actuator is attached to at least one rod that extends through clearance holes of a clamp bracket and is connected to a steering arm of the outboard motor. The one or more rods attached to the piston are aligned coaxially with an axis of rotation about which the swivel bracket rotates and the outboard motor is trimmed.
U.S. Pat. No. 6,402,577, which issued to Treinen et al. on Jun. 11, 2002, discloses an integrated hydraulic steering system for a marine propulsion unit. The system is provided in which a steering actuator is an integral portion of the support structure of a marine propulsion system. A steering arm is contained completely within the support structure of the marine propulsion system and disposed about its steering axis. An extension of the steering arm extends into a sliding joint which has a linear component and a rotational component which allow the extension of the steering arm to move relative to a movable second portion of the steering actuator. The movable second portion of the steering actuator moves linearly within a cylinder cavity formed in a first portion of the steering actuator.
U.S. Pat. No. 6,406,340, which issued to Fetchko et al. on Jun. 18, 2002, describes a twin outboard motor hydraulic steering system. The assembly applies a force to the tiller arms of twin marine, outboard propulsion units and rotates the propulsion units about a steering axis between a center position and hard over positions to each side of the center position. Each propulsion unit is supported for arcuate movement about a tilt axis which is generally perpendicular to the steering axis. There is a hydraulic steering apparatus mounted on a first of the propulsion units which includes a hydraulic cylinder pivotally connected to a member which is pivotally mounted on the tiller arm of the first propulsion unit.
U.S. Pat. No. 6,821,168, which issued to Fisher et al. on Nov. 23, 2004, discloses a power steering system for a marine vessel. An outboard motor is provided with an internally contained cylinder and movable piston. The piston is caused to move by changes in differential pressure between first and second cavities within the cylinder. By adding a hydraulic pump and a steering valve, the hydraulic steering system described in U.S. Pat. No. 6,402,577 is converted to a power hydraulic steering system by adding a hydraulic pump and a steering valve to a manual hydraulic steering system.
U.S. Pat. No. 6,883,451, which issued to Takada et al. on Apr. 26, 2005, describes an outboard motor steering system. The steering system is for an outboard motor mounted on a stern of a boat with an internal combustion engine at is its upper portion and a propeller with a rudder at its lower portion powered by the engine to propel and steer the boat. The system includes a swivel shaft connected to the propeller to turn it relative to the boat, a swivel case fixed to the outboard motor and rotatably accommodating the swivel shaft, and a hydraulic actuator connected to the swivel shaft to rotate it. The actuator has a shape whose height is larger than its width and is installed in such a manner that a direction of the height is in parallel with a vertical direction, so as not to project outside a profile of the outboard motor, obtained by looking down the outboard motor from downward, regardless of a steering angle of the outboard motor.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.